Some APL symbols need adjusting

[abrudz]

#47 added APL symbols, but some of the so-called (former) overstrikes are a little off:

The last two entries need description:

• The APL vendors standardised on using ∊ rather than ∈ (though one implementation uses ∈), but either way, the epsilon should be "lunate" rather than "inverted-3 form" since it derives from the membership symbol.
• The convention is that the horizontal bar in ⊖ touches the outer ring. This means the bar has to be elongated compared to -, but this is already the case in ⌿, ⍀, and ⌹, so it is a consistent deviation.

For easy look-up, the raw table is here:

JetBrains	APL385 Unicode
∪ + | = ⍦	∪ + | = ⍦
⊤ + ⊥ = ⌶	⊤ + ⊥ = ⌶
, + - = ⍪	, + - = ⍪
| + ○ = ⌽	| + ○ = ⌽
[ + ] = ⌷	[ + ] = ⌷
0 + ~ = ⍬	0 + ~ = ⍬
⎕ + / = ⍁	⎕ + / = ⍁
⎕ + \ = ⍂	⎕ + \ = ⍂
⎕ + ∨ = ⍌	⎕ + ∨ = ⍌
⎕ + ∧ = ⍓	⎕ + ∧ = ⍓
∈/∊ + _ = ⍷	∊ + _ = ⍷
⊖ like ⌿ ⍀ ⌹	⊖ like ⌿ ⍀ ⌹